Recent development of networks has expanded a framework in which a user logs via a network into a remote computer located at a distance from the user's local computer and performs operations on the remote computer, as represented by a thin client.
In such a framework, a mode is assumed in which a USB device is connected to the local computer and this USB device is recognized for use on the remote computer. For example, when a USB camera is used that can fetch dynamic images in a computer (PC) by USB connection, direct connection of the USB camera to the remote computer located at a distance is not easy. Therefore, most users wish to connect the camera to their own local computer and use it on the remote computer.
A technique called “USB Redirect” is known for recognizing and using such a USB device connected to the local computer on a remote computer (Japanese Patent Application Laid-Open No. 2008-210115). Further, there also exists a technique called “USB Device Server” by which a USB device is connected to a special device server, rather than a local computer, and this connected USB device can be used from another computer (Japanese Patent Application Laid-Open No. 2008-287453).
However, with the above-described USB Redirect technique, data in a USB protocol format and data in a network protocol format have to be converted into each other each time data communication with the USB device is performed. The resultant problem is a decrease in communication performance caused by communication delay and overhead. With many of USB devices exchanging data within a short time and with a high frequency, this problem becomes evident, in particular, for a USB camera that exchanges data real-time.
Further, the aforementioned USB device server is configured to be compatible with only a specific USB device such as a storage or a printer and to be dependent on an OS. Therefore, such a server has difficulty being applied to the USB device such as a USB camera that exchanges data real-time.